Quality enhancement of recycled asphalt product using warm mix asphalt technology

Abstract

The challenge of utilizing Recycled Asphalt is the secondary aging of aged binders from Reclaimed Asphalt Pavement (RAP) in Hot Mix Asphalt (HMA) technology. This research aims to lower the production temperature of HMA by using an organic additive (Sasobit) and reducing the preheating temperature of RAP. Marshall mix designs were developed for Wearing Course, replacing different proportions of RAP (0%, 20%, 30%, and 40%) using Warm Mix Asphalt (WMA) technology, alongside a conventional HMA control sample. The mechanical and volumetric properties of the WMA-RAP asphalt mixtures were evaluated through the Marshall test. Results show that WMA-RAP mixtures containing up to 40% RAP have comparable properties to the control sample, meeting the requirements outlined by the Institute of Construction Training & Development (ICTAD). Marshall samples for 40% WMA-RAP mix were prepared with various RAP preheating temperatures at previously determined optimum binder content. Based on the findings, it is recommended to incorporate a WMA design with 40% RAP, preheated at 110°C, and virgin aggregate preheated at 160°C in asphalt production. This approach avoids RAP's secondary aging and optimizes its use as an environmentally sustainable solution.